问题
I am trying to send data to a server from my client .the client sends messages to a server ,every message is 36 bytes and in this message every 4 byte is a field and in server part i should be able to detect that field from the message that client sends .Suppose i have this data :
A=21
B=32
c=43
D=55
E=75
F=73
G=12
H=14
M=12
In the client i should send this values as a single message .as you can see my message has 9 field and every field is 4 byte integer and all message is 36 byte.
So in server part when the message is received i should be able to separate the message and find the value of the fields .
In client application i am using this structure to send message to my server :
m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// Cet the remote IP address
IPAddress ip = IPAddress.Parse(GetIP());
int iPortNo = System.Convert.ToInt16("12345");
// Create the end point
IPEndPoint ipEnd = new IPEndPoint(ip, iPortNo);
// Connect to the remote host
m_clientSocket.Connect(ipEnd);
if (m_clientSocket.Connected)
{
Object objData = ?!!!!;//My message
byte[] byData = System.Text.Encoding.ASCII.GetBytes(objData.ToString());
if (m_clientSocket != null)
{
m_clientSocket.Send(byData);
}
Thread.Sleep(4000);
}
}
And in server part i am using this code to receive the data:
public void OnDataReceived(IAsyncResult asyn)
{
try
{
SocketPacket socketData = (SocketPacket)asyn.AsyncState;
int iRx = 0;
// Complete the BeginReceive() asynchronous call by EndReceive() method
// which will return the number of characters written to the stream
// by the client
iRx = socketData.m_currentSocket.EndReceive(asyn);
char[] chars = new char[iRx + 1];
System.Text.Decoder d = System.Text.Encoding.UTF8.GetDecoder();
int charLen = d.GetChars(socketData.dataBuffer,
0, iRx, chars, 0);
System.String szData = new System.String(chars);
MessageBox.Show(szData);
// Continue the waiting for data on the Socket
WaitForData(socketData.m_currentSocket);
}
catch (ObjectDisposedException)
{
System.Diagnostics.Debugger.Log(0, "1", "\nOnDataReceived: Socket has been closed\n");
}
catch (SocketException se)
{
}
}
Here is the other part of my server code :
public void OnClientConnect(IAsyncResult asyn)
{
try
{
// Here we complete/end the BeginAccept() asynchronous call
// by calling EndAccept() - which returns the reference to
// a new Socket object
m_workerSocket[m_clientCount] = m_mainSocket.EndAccept(asyn);
// Let the worker Socket do the further processing for the
// just connected client
WaitForData(m_workerSocket[m_clientCount]);
// Now increment the client count
++m_clientCount;
// Display this client connection as a status message on the GUI
String str = String.Format("Client # {0} connected", m_clientCount);
// Since the main Socket is now free, it can go back and wait for
// other clients who are attempting to connect
m_mainSocket.BeginAccept(new AsyncCallback(OnClientConnect), null);
}
catch (ObjectDisposedException)
{
System.Diagnostics.Debugger.Log(0, "1", "\n OnClientConnection: Socket has been closed\n");
}
}
public class SocketPacket
{
public System.Net.Sockets.Socket m_currentSocket;
public byte[] dataBuffer = new byte[36];
}
In my form_load of server part i have this code:
ipaddress = GetIP();
// Check the port value
string portStr = "12345";
int port = System.Convert.ToInt32(portStr);
// Create the listening socket...
m_mainSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
IPEndPoint ipLocal = new IPEndPoint(IPAddress.Any, port);
// Bind to local IP Address...
m_mainSocket.Bind(ipLocal);
// Start listening...
m_mainSocket.Listen(4);
// Create the call back for any client connections...
m_mainSocket.BeginAccept(new AsyncCallback(OnClientConnect), null);
in fact i am trying to implement this link :
http://www.codeguru.com/csharp/csharp/cs_misc/sampleprograms/article.php/c7695/Asynchronous-Socket-Programming-in-C-Part-I.htm
My problem is how can i send my message as a 36 bytes via client and get and separate that from server ?
Every four bytes is a field and i should be able to get this value .
回答1:
Seems like all you need is 2 methods to convert integers to byte-array and vice versa:
byte[] packet = CreateMessage(21,32,43,55,75,73,12,14,12);
//send message
//recv message and get ints back
int[] ints = GetParameters(packet);
....
public byte[] CreateMessage(params int[] parameters)
{
var buf = new byte[parameters.Length * sizeof(int)];
for (int i = 0; i < parameters.Length; i++)
Array.Copy(BitConverter.GetBytes(parameters[i]), 0, buf, i * sizeof(int), sizeof(int));
return buf;
}
public int[] GetParameters(byte[] buf)
{
var ints = new int[buf.Length / sizeof(int)];
for (int i = 0; i < ints.Length; i++)
ints[i] = BitConverter.ToInt32(buf, i * sizeof(int));
return ints;
}
回答2:
You're doing it wrong. If you want to transmit binary data, do not encode it as a string. There are multiple ways to do this:
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct Msg
{
public int A, B, C, D, E, F, G, H, M;
}
Then use the Marshal class to get the bytes. This will get you little-endian on the wire data though.
Another method is to use a BinaryWriter. Same thing, little-endian data unless you convert it yourself or use an alternate version of BinaryWriter.
Then, it's much easier to use a NetworkStream, because this class will handle packet fragmentation for you. Here's the sending code using the BinaryWriter method:
using (var stream = new NetworkStream(stocket))
{
var writer = new BinaryWriter(stream);
writer.Write(21);
writer.Write(32);
// etc
}
Same thing on the client side using a NetworkStream and a BinaryReader.
NB: You can use async I/O with NetworkStream using the async/await feature.
来源：https://stackoverflow.com/questions/24586648/send-binary-data-and-read-the-values-of-that-using-async-socket-programming